A Comparative Study of Strain Gauge-Based RLDA and Load Cell-Based RLD Methods for Assessing Structural Durability Loads in Engine Mounts

In the ongoing Road Load Data Acquisition (RLDA) for engine mounts, a load cell arrangement is being utilized, where the load cell is required to be placed in between the mount arm and an additional tower bracket. This configuration required the design of a custom mount arm with a crank in the Z direction, secured with a single bolt to accommodate the load cell. However, this method has revealed significant load coupling in the Z and X directions, resulting in failures of the Main Rubber Element (MRE) in the engine mounts. To mitigate these issues, a strain gauge-based RLDA approach was investigated as an alternative. The optimal locations for strain gauge placement were determined using the inverse matrix method with the assistance of Computer-Aided Engineering (CAE) analysis. Strain gauges were then installed at these identified locations on the mount arm. The modified engine mount, now equipped with strain gauges, was tested in a real vehicle under standardized driving conditions and tracks. The strain data obtained was subsequently converted into load signals, which demonstrated a substantial reduction in coupling effects compared to the load cell arrangement. This method not only provided more accurate load data but also presented a reliable alternative for RLD collection in engine mounts. A detailed case study is included to illustrate the correlation and effectiveness of this newly proposed RLDA process. Keywords: Engine Mounts, Road Load Data Acquisition (RLDA), Strain Gauge, Load Cell